<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <style>
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    .box {
      height: 300px;
      background-color: pink;
      padding-top: 30px;
      margin: 0 auto;
    }

    .box1 {
      width: 500px;
      height: 80px;
      background-color: #e4e4e4;
      border: 1px solid black;
      margin: auto;
      padding: 10px;
    }

    .box2 {
      width: 500px;
      height: 80px;
      background-color: #e4e4e4;
      border: 2px solid black;
      margin: 50px auto;
      padding: 10px;
    }
  </style>
  <body>
    <div class="box">
      <div class="box1">
        height: 80px; <br />
        border: 1px solid black;
      </div>
      <div class="box2">
        height: 80px; <br />
        border: 1px solid black;
      </div>
    </div>
    <h3>配置【截屏】>【显示】>【边框宽度】为 0px</h3></div></div>
  </body>
</html>
